Gastric Motility and Pancreatic Function Flashcards Preview

07. Year 2: Alimentary System > Gastric Motility and Pancreatic Function > Flashcards

Flashcards in Gastric Motility and Pancreatic Function Deck (62)
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1

What is gastric motility?

Peristaltic waves from the body of the stomach to the antrum (contractions)

2

How does contractions strength vary across the stomach?

Is different in different areas

3

What is the contraction strength like in the body of the stomach?

Weak because it has a thin muscle

4

What is the contraction strength like in the antrum of the stomach?

Powerful because has a thick muscle

5

Where in the stomach does mixing occur?

Antrum

6

What happens when the pyloric sphincter is contracted?

Small quantitiy of gastric contents (chyme) enters the duodenum, further mixing occurs as antrul contents are forced back towards the body

7

What is gastric contents known as?

Chyme

8

What is the gastric peristaltic wave produced by?

Peristaltic rhythm

9

What is the peristaltic rhythm generated by?

Pacemaker cells in the longitudinal muscle layer

10

What is the rate of the peristaltic rhythm?

About 3/min

11

How does the signal from the peristaltic rhythm travel through the longitudinal muscle layer?

Gap junctions

12

What must be reached for the stomach to contract?

Action potential must reach threshold

13

What is the slow wave rhythm of the peristaltic rhythm known as?

Basic electrical rhythm (BER)

14

What is the action potential size proportional to?

Tension on the stomach wall

15

Explain the hormonal/neural control of contractions?

Gastrin increases contraction

Distension of stomach wall causes long/short reflexes which increases contraction

Fat/acid/amino acid/hypertonicity in duodenum inhibits motility (contraction)

16

How does gastrin impact contraction?

Increases

17

How does distension of stomach wall impact contraction?

Increases

18

How does the presence of fat, acid, amino acid, or hypertonicity in the duodenum impact contraction?

Decreases

19

What controls the force of contractions?

Frequency of action potentials

20

What secretes bicarbonate?

Brunner's glands duct cells

21

In what layer are Brunner's glands found?

Submucosal

22

What is neutralisation of acid in the duodenum done by?

Bicarbonate

23

What happens to the water and carbon dioxide produced during acid neutralisation?

Water flows down the gut and carbon dioxide diffuses away

24

Why is it important that the duodenum is not acidic?

It would denature enzymes from the pancreas and damage the duodenum epithelium which needs to absorb things such as iron

25

What does acid in the duodenum trigger?

Long (vagal) and short (ENS) reflexes causing HCO3 secretion

Release of secretin from S cells causing HCO3 secreiton

26

What are long reflexes controlled by?

Vagas nerve

27

What are short reflexes controlled by?

ENS reflexes

28

What does secretin cause?

Bicarbonate to be secreted from the pancreas and liver which will end up in the duodenum as well as from Brunner's glands in the duodenum

29

How does acid neutralisation impact secretin release?

Inhibitis secretin release (negative feedback control)

30

What are the 3 parts of the pancreas?

Head (located within curvature of duodenum)

Body

Tail (extends to spleen)